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Monday, April 27, 2015

Actin is a globular, roughly 42-kDa protein found in almost all
eukaryotic cells. It is also one of the most highly conserved proteins,
differing by no more than 20% in species as diverse as algae and humans.
Actin is the monomeric subunit of two types of filaments in cells:
microfilaments, one of the three major components of the cytoskeleton,
and thin filaments, part of the contractile apparatus in muscle cells.
Thus, actin participates in many important cellular processes including
muscle contraction, cell motility, cell division and cytokinesis,
vesicle and organelle movement, cell signaling, as well as the
establishment and maintenance of cell junctions and cell shape.

AAT Bioquest’s phalloidin conjugates selectively binds to F-actins. Used
at nanomolar concentrations, phalloidin derivatives are convenient
probes for labeling, identifying and quantitating F-actins in
formaldehyde-fixed and permeabilized tissue sections, cell cultures or
cell-free experiments. Phalloidin binds to actin filaments much more
tightly than to actin monomers, leading to a decrease in the rate
constant for the dissociation of actin subunits from filament ends,
essentially stabilizing actin filaments through the prevention of
filament depolymerization. Moreover, phalloidin is found to inhibit the
ATP hydrolysis activity of F-actin. Phalloidin functions differently at
various concentrations in cells. When introduced into the cytoplasm at
low concentrations, phalloidin recruits the less polymerized forms of
cytoplasmic actin as well as filamin into stable “islands” of aggregated
actin polymers, yet it does not interfere with stress fibers, i.e.
thick bundles of microfilaments. The property of phalloidin is a useful
tool for investigating the distribution of F-actin in cells by labeling
phalloidin with fluorescent analogs and using them to stain actin
filaments for light microscopy. Fluorescent derivatives of phalloidin
have turned out to be enormously useful in localizing actin filaments in
living or fixed cells as well as for visualizing individual actin
filaments in vitro. Fluorescent phalloidin derivatives have been used as
an important tool in the study of actin networks at high resolution.
AAT Bioquest offers a variety of fluorescent phalloidin derivatives with
different colors for multicolor imaging applications as summarized in
the following table.

Current Range

Catalogue No.

Product Name

Unit

MW

Ex (nm)

Em (nm)

5301-AAT

Phalloidin

1 mg

788.88

N/A

N/A

5302-AAT

Phalloidin Amine

100 μg

901.91

N/A

N/A

23100-AAT

Phalloidin-AMCA Conjugate

300 tests

~1000

353

442

23101-AAT

Phalloidin-Fluorescein Conjugate

300 tests

~1100

492

518

23102-AAT

Phalloidin-Tetramethylrhodamine Conjugate

300 tests

~1200

546

575

23103-AAT

Phalloidin-California Red Conjugate*

300 tests

~1000

583

605

23110-AAT

Phalloidin-iFluor™ 350 Conjugate

300 tests

~1000

353

442

23111-AAT

Phalloidin-iFluor™ 405 Conjugate

300 tests

~1400

400

421

23115-AAT

Phalloidin-iFluor™ 488 Conjugate

300 tests

~1900

493

517

23116-AAT

Phalloidin-iFluor™ 514 Conjugate

300 tests

~1800

520

547

23117-AAT

Phalloidin-iFluor™ 532 Conjugate

300 tests

~1800

542

558

23119-AAT

Phalloidin-iFluor™ 555 Conjugate

300 tests

~1300

556

574

23122-AAT

Phalloidin-iFluor™ 594 Conjugate

300 tests

~1600

590

618

23125-AAT

Phalloidin-iFluor™ 633 Conjugate

300 tests

~2100

634

649

23127-AAT

Phalloidin-iFluor™ 647 Conjugate

300 tests

~2200

650

665

23128-AAT

Phalloidin-iFluor™ 680 Conjugate

300 tests

~2700

681

698

23129-AAT

Phalloidin-iFluor™ 700 Conjugate

300 tests

~3000

692

708

23130-AAT

Phalloidin-iFluor™ 750 Conjugate

300 tests

~3300

752

778

23131-AAT

Phalloidin-iFluor™ 790 Conjugate

300 tests

~2800

787

808

*Excellent replacement to Texas Red-phalloidin conjugate due to their essentially identical spectral properties.

Stratech Scientific is a distributor of high quality, competitively
priced, reliable products for research laboratories throughout the UK
and Europe. Please contact us to find out which ranges we can supply in
your country.